package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.util.Collections;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author <a href="https://gitee.com/hebei-dynasty-competition">搜一码赛</a>
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;

    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;

    private static  final DefaultRedisScript<Long> SECKILL_SCRIPT;
        static {
            SECKILL_SCRIPT=new DefaultRedisScript<>();
            SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
            SECKILL_SCRIPT.setResultType(Long.class);
        }
        //创建一个消息队列
    private BlockingQueue<VoucherOrder> orderTasks=new ArrayBlockingQueue<>(1024 *1024);
        //创建线程池
    private static final ExecutorService SECKILL_ORDER_EXECUTOR= Executors.newSingleThreadExecutor();
    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }
    private class VoucherOrderHandler implements  Runnable{
        @Override
        public void run() {
            while(true){
                //1.获取队列中的订单信息
                try {
                    VoucherOrder voucherOrder=orderTasks.take();
                    //2.创建订单
                    handleVoucherOrder(voucherOrder);
                } catch (Exception e) {
                    log.error("处理订单异常",e);
                }

            }
        }
    }

    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        //1.获取用户
        Long userId = voucherOrder.getUserId();
        //2.创建锁对象
        RLock redisLock = redissonClient.getLock("lock:order:" + userId);
        //3.尝试获取锁
       boolean isLock=redisLock.tryLock();
       //4.判断获取锁是否成功
       if(!isLock){
           //获取锁失败,直接返回失败或者重试
           log.error("不允许重复下单!");
           return;
       }
       try {
           //注意:由于是spring的事务是放在threadLocal中,此时的是多线程,事务会失效
           proxy.createVoucherOrder(voucherOrder);
       }finally {
           //释放锁
           redisLock.unlock();
       }

    }

    /**
     * 抢购优惠券订单
     *
     * @param voucherOrder
     */
    @Override
//    public Result addseckillVoucher(Long voucherId) {
//        //1.查询优惠卷
//        SeckillVoucher seckillVoucher = seckillVoucherService.getById(voucherId);
//        //2.判断优惠卷日期是否生效
//        //2.1 优惠卷还没开始
//        if(seckillVoucher.getBeginTime().isAfter(LocalDateTime.now())){
//            return Result.fail("优惠卷还没开始");
//        }
//        //2.2 优惠卷活动时间过期
//        if(seckillVoucher.getEndTime().isBefore(LocalDateTime.now())){
//            return Result.fail("优惠券活动已经结束");
//        }
//        //3.检验优惠券库存是否充足
//        // 4.判断库存是否充足
//        if (seckillVoucher.getStock() < 1) {
//            // 库存不足
//            return Result.fail("库存不足！");
//        }
//        Long userId=UserHolder.getUser().getId();
//        //创建锁对象
////        SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
//        RLock lock = redissonClient.getLock("lock:order:" + userId);
//        //获取锁
//        boolean isLock = lock.tryLock();
//        //判断是否获取锁成功
//        if(!isLock){
//            return Result.fail("不允许重复下单");
//        }
//        try {
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId);
//        }finally {
//            //释放锁
//            lock.unlock();
//        }
////        //事务提交之后才释放锁,解决线程并发带来的错误
////        synchronized (userId.toString().intern()) {
////            //获取代理对象(使事务生效)
////            //6.然后返回订单id
////            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
////            return proxy.createVoucherOrder(voucherId);
////        }
//    }

    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder){
        //一人一单功能
        //5.2用户id
        Long userId = voucherOrder.getUserId();
            //查询订单
            int count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
            //判断库存是否存在
            if (count > 0) {
                log.error("用户已经购买过了");
                return;
            }
            //5，扣减库存
            //乐观锁,只要数据库内库存大于0就可以进行修改
            boolean success = seckillVoucherService.update()
                    .setSql("stock= stock -1")
                    .eq("voucher_id", voucherOrder.getVoucherId())
                    .gt("stock", 0)
                    .update();
            if (!success) {
                //扣减库存
                log.error("库存不足");
                return;
            }

            save(voucherOrder);

    }

    private IVoucherOrderService proxy;
    /**
     * 抢购优惠券订单优化 异步秒杀
     */
    @Override
    public Result addseckillVoucher(Long voucherId) {
        //获取用户
        Long userId = UserHolder.getUser().getId();
        //1.执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(), userId.toString()
        );
        //2.判断结果是为0
        int r=result.intValue();
        if(r!=0){
            //2.1 不为0,代表没有资格
            return Result.fail(r == 1 ?"库存不足":"不能重复下单");
        }
        //2.2 为0,有购买资格,把下单信息保存到阻塞队列
        VoucherOrder voucherOrder = new VoucherOrder();
        //2.3订单id
        long orderId= redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);
        //2.4用户Id
        voucherOrder.setUserId(userId);
        //2.5代金券id
        voucherOrder.setVoucherId(voucherId);
        //2.6放入阻塞队列
        orderTasks.add(voucherOrder);
        //3.获取代理对象
        proxy=(IVoucherOrderService)AopContext.currentProxy();
        //4.返回订单id
        return  Result.ok(orderId);
    }

}
